The polynomial equation x3 - 4x²+2x+10 - 42 -5x-3 has complex roots 3 + 21. What is the other root? Use a graphing calculator and a system of equations.
O-3
O-1
O 3
O 10

9514 1404 393

  B.  -1

Step-by-step explanation:

The graphing calculator shows the left-side function intersects the right-side function at x = -1.

δabc ≅ δdcb by sas because

db ≅ ac . . given (side)

bc ≅ bc . . reflexive property (side)

∠dbc ≅ ∠ acb . . alternate interior angles where transversal bc crosses parallel lines bd and ac (included angle)